1. Field of the Invention
The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition that causes a reaction upon irradiation with an actinic ray or radiation to change in the property, and a pattern forming method using the composition. More specifically, the present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition for use in the production process of a semiconductor such as IC, in the production of a circuit substrate of liquid crystal, thermal head or the like, in other photofabrication processes, or in the lithographic printing plate or acid-curable composition, and a pattern forming method using the composition.
The present invention also relates to a novel polymerizable compound useful as a raw material of a polymer compound for use in the production of a semiconductor such as IC, in the production of a circuit substrate of liquid crystal, thermal head or the like, or in other photofabrication processes, and a polymer compound having a unit corresponding to the polymerizable compound. More specifically, the present invention relates to a novel polymerizable compound useful as a raw material of a polymer compound for use in the process where a far ultraviolet ray or the like at 250 nm or less, preferably 220 nm or less, is used as the exposure light source or an electron beam or the like is used as the irradiation source, and a corresponding polymer compound.
2. Description of the Related Art
The chemical amplification resist forms a pattern on a substrate by generating an acid in the exposed area when irradiated with radiation such as far ultraviolet light and through a reaction using the acid as the catalyst, causing the area irradiated with actinic radiation and the non-irradiated area to change in the solubility for a developer.
In the case of using a KrF excimer laser as the exposure light source, a resin having small absorption in the region of 248 nm and having a basic skeleton of poly(hydroxystyrene) is primarily used as the main component and this is an excellent system capable of forming a good pattern with high sensitivity and high resolution as compared with conventional naphthoquinone-diazide/novolak resin systems.
In the case of using a light source of emitting light at shorter wavelengths, for example, in using an ArF excimer laser (193 nm) as the light source, a satisfactory pattern cannot be formed even by the above-described chemical amplification system because the compound having an aromatic group substantially has large absorption in the region of 193 nm.
In order to solve this problem, various resists containing an alicyclic hydrocarbon structure have been developed for use with an ArF excimer laser. However, in view of integrated performance as a resist, it is very difficult at present to find out an appropriate combination for the resin, photoacid generator, additive, solvent and the like used. Moreover, at the time of forming a fine pattern with a line width of 100 nm or less, improvements in terms of the line edge roughness performance and resolution of a line pattern are being demanded.
As already discovered, the line edge roughness performance can be enhanced by incorporating a repeating unit having a specific lactone structure into the above-described resin having an alicyclic hydrocarbon structure. For example, JP-A-2005-352466 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”) describes a resist composition using a resin containing a repeating unit having a spacer-type norbornane structure, and JP-A-2007-156450 describes a resist composition using a resin containing a repeating unit having a cyano group and a norbornane structure.
However, in view of integrated performance as a resist, suppression of pattern variation attributable to fluctuation in the focus position at the exposure (defocus latitude: DOF) and reduction in the development defect are demanded.
As described above, a polymer compound comprising a repeating unit having a spacer-type norbornane skeleton is described in JP-A-2005-352466 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), and a polymer compound comprising a repeating unit having a cyano group and a norbornane structure is described in International Publication No. 07/037213, pamphlet.
However, the repeating unit having a spacer-type norbornane skeleton has a problem in the affinity for a developer, whereas in the case where a cyano group is introduced into a norbornane structure, solubility in a solvent used for resists in general is insufficient.